[Complexicate]

I'm glad you prefaced this with "(now)" ie: hindsight. There's always a considerable chance that tests of the untested / unproven will remain inconclusive, even if there's some evidence we should find something.

It's extremely risky to allocate a huge amount of finite resources to these unknowns, when there are so many areas we KNOW we can help advance with those finite resources. The fact that he was ready to retire, if the picture came back with barely anything in it, gives a sense of how bad that waste of resources would have been.

Future us might not think it is such a gamble to send a probe to look for life in the oceans of Saturn's moon Enceladus. There's evidence of abiogenesis from deep sea vents on Earth, and Enceladus has very similar conditions. But present us knows there are so many unknowns and possibilities of failure even if something is there. And there are so many other useful ways to use the finite resources of our space program.

It took a lot of courage on Bob Williams' part to explore this.